Here are some players who once randomly, improbably, found themselves on the Mets' Opening Day roster.
Most of these players actually appeared in the Opening Day lineup...
Eric Valent, 2005
Tucked in right field on Opening Day as Pedro Martinez took the mound to make his Mets debut in Cincinnati against the Reds (as Carlos Beltran debuted as well) was Valent, who hit for the cycle against the Expos in Montreal in 2004 but retired from baseball after 2005.
Chan Ho Park, 2007
Park had a successful career in MLB, but his time with the Mets was Moonlight Graham-esque. He wound up on the Opening Day roster, pitched one game, gave up seven runs, and got sent down to the minors, never to play for the Mets again.
Gary Matthews Jr., 2010
The one-year wonder and owner of one of the all-time great plays by an outfielder finished his career as an Opening Day member of the Mets in 2010. He ended up playing only 35 games and hitting .190 in that span, which led to his release in June.